Introduction Isolated unilateral hypoglossal nerve injury is rare in the Paediatric population. Presenting features include dysphagia. Of cases reviewed in the literature, neoplastic, vascular, infective, inflammatory and traumatic pathologies are recognised causes; the remaining cases are classified idiopathic. The mainstay of investigation is MRI imaging, and treatment is supportive.
Case report We report a six month old female patient reviewed in Paediatric clinic presenting with a longstanding history of difficulty feeding. There were also concerns with the patient’s speech when forming lala, baba and tata sounds. The patient was born at term, of normal vaginal delivery, with no significant neonatal or perinatal problems. Apart from some speech impairment, the child was developmentally normal. There was a strong family history of epilepsy. On examination there was no drooling, the tongue was bulkier on the right, with reduced mobility and fasciculation on the left side; on protrusion the tongue deviated to the left. The remaining cranial nerve examination was normal, with normal palatal movements and gag reflex. The rest of the examination was normal.
MRI brain was normal. The child at 18 month follow up had a normal examination with appropriate growth and neuro-development but with continuing asymmetry of the tongue.
Discussion The literature suggested a sieve to identify the following aetiological processes: vascular, neoplastic, infective, traumatic, inflammatory and idiopathic. Only 3 papers identified idiopathic causes of nerve palsy, all of which recovered with supportive therapy in 6 months. Only structural lesions did not improve with time.
Conclusion Isolated unilateral hypoglossal nerve palsy is rare and can be idiopathic in origin. MRI is the investigation of choice to rule out structural lesions, and treatment is tapered toward aetiology with supportive management.